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(No Model.) 2 Sheets-Sheet I.

` A. BAUOHERE. KILN POR BURNING lLIME, CEMENT, &c.

No. 598,893. Patented Feb. 1'5, 1898.

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(No Model.) .v 2 Sheets-Sheet 2.. A. BAUGHERE.

KILN POR BURNING LlME, CEMENT, zc.

No. 598,893. Patented Feb. 15, 1898.

7| fly? 11g-Z Z i y Aj' w Y X UNITED STATES PATENT OFFICE.

ANTOINE BAUCHERE, OF BOULOGNE, FRANCE.

KILN FOR BURNING LIME, CEMENT, 840.

SPECIFICATION forming part of Letters Patent No. 598,893, dated February 15, 189s.

Application filed J'une 22,1896. Serial No. 596,480. (No model.) lPatentedin France April 27, 1894, No. 238,098; in Belgium May 12, 1894,1Tox 109,956,l in England May 15,1894, No. 9,545, and in GermaiyMay 2l, 1894, No. 80,655.

To a/ZZ whom it may concern:

Be it known that I, ANTOINE BAUCHRE, engineer, a citizen of the Republic of France, residing in Boulogne-sur-Mer, France, have invented certain Improvements in Continuous or Running Kilns for Burning Lime, Oement, and other Similar Materials, (for which I have obtained a patent in France, dated April 27, 1894, No. 238,093; in Belgium, dated May 12, 1894, No. 109,956; in Great Britain, dated May 15, 1894, No. 9,545, and in Germany, dated May 2l, 1894, No. 80,655,) of which the following is a specification.

The invention referred to in this specification relates to improvements in continuous kilns for ,the burning of lim'e, natural and Portland cement, and other similar products.

The objects of these improvements are essentially the following: first, the regular, continuous, and uniform burning of the products mentioned above; second, the preventionof adhesion or clustering of the material to the walls of the kiln; third, Vthe complete and continuous combustion ofthe gases without interruption even during the periods when the kiln is being charged, and the utilization of the waste heat. in substantially the following manner:

In order to obtain a continuous, uniform, and regular burning, the temperature must be kept peroeptibly constant in the zone of combustion. For this effect two gas-outlets are used, one of them, being continuous, located just above the zone of combustion of the material, and the other, being intermittent, placed at the upper part of thecharging-cone. The continuous outlet is isolated from the charging-aperture by the material contained in the charging-cone and remains in communication with the draft-fines, and if the dampers of the chimney are well regulated this outlet draws out during every charging the gases evolved during the calcination. The intermittent outlet, automatically closed by the charging-cone,bein g opened permits of the chargings being effected without any gas flowing back or cold air being admitted. In this manner the chargings can be made without interfering with the regular operation of the kiln no matter how long a time they may take.

These results are obtained In order to prevent adhering or clustering of the material to the Walls of the kiln, the charging must be performed in such a manner that the fuel, distributed automatically from the center toward the periphery of the kiln by the charging itself, reaches a point near this periphery in a quantity only just sufficient to obtain the limit of burning of the cement when it comes in contact with the walls. Moreover, this charging must be done in such a manner that the pressure of the material in contact with thewalls of the kiln at the zone of combustion is feeble enough to render clustering impossible. For this purpose a break or recess has been arranged between the charging-cone and the top of the shaft of the kiln proper, which at this spot causes the raw material as it descends into the kiln to pile up in a slanting mass and to inclose the thin layer of fuel, which is then no longer in contact with the Walls of the kiln.

In order to obtain the complete continuous combustion of the gases disengaged by the burning, it is necessary to maintain an even temperature in the combustion-chamber of these gases. tem of conduit-pipes permitting, on the one hand, the admission only of heated air into the gas-combustion chamber even during the chargings, and the proper mixing of the same with the gases, and, on the other hand, the

heating of the gases coming from the top of the charging-cone, so as to bring them gradually to the temperature of the hotter gases coming from the zoney of combustion.

In the accompanying drawings, Figure 1 is a vertical section of the dome of a continuous kiln built according to my invention. Fig. 2 is another vertical section'made at right angles to the former. Fig. 3 is a longitudinal section made along the line 3 3 of Fig. 1. Fig. 4 is a horizontal section along the linev 4 4 of Fig. 1. Fig. 5 is a horizontal section along the line 5 5 of Fig. 2 from the gas-conduit to the chimney. Fig. 6 is a horizontal section along the line 6 6 of Fig. 2. Fig. 7' is a vertical section along the line 7 7 of Fig. 2. Fig. 8 is a vertical section along theline 8 8 of Fig. 1.

The kiln illustrated is'of suitable capacity and shape.' It is surmounted by a charging For this purpose there is a sys- IDO dome or cone A, which leaves between itself and the top of the shaft A of the kiln proper a break or recess a, form ed by an arched part. This break constitutes the outlet, called lower con tin uous outlet. It communicates with flues B, leading on one side to the chimney by means of a large vertical conduit C, called the gas-combustion chamber, and on the other side by means of conduits c and a iiue C', surrounding the charging-cone A, Figs. l, 2, 4, and '7, and opening through numerous apertures c' into the gas-combustion chamber or conduit C.

At the top of the charging-cone A there is another gas-outlet, called the upper intermittent outlet, consisting of a circular flue D, perforated on its inner side to communicate with the cone A and subdivided into a certain number of sectors, each of them communicating with a conduit d, opening into a flue D', located directly over the iiue C and, like the latter, surrounding the charging-cone A. This flue D opens likewise into the gascombustion chamber or conduit C by numerous apertures d.

The fines C' of the lower continuous outlet and the flue Dl of the upper intermittent outlet are separated by simple metal plates fm. This arrangement is made for the purpose of heating the gases of the upper outlet and bringing them to the temperature of the gases 0f the lower outlet, which are evidently hotter, as they are taken near the zone of combustion situated on the top of the shaft A at lthe rear.

The conduits d d d d of the upper outlet are each provided with a damper r, connected by a chain w, running over suitable pulleys, witha cover E closing the entrance to the charging-cone A. The dampers r and the cover E so connected are equiposed, so as to facilitate their working. This arrangement is intended to close automatically the dampers r each time the cover E is raised for a charging and to keep said dampers open while said cover remains closed between two chargings.

Below the flue C there are horizontal conduits e, opening at one end into the open air, Figs. 2, 5, 6, and 7, and at the other end into the gas-combustion chamber or conduit C. These conduits admit the outside air and feed it into the said combustion-chamber C. It will be perceived, Fig. 5, that several of these conduits are connected with one circular conduit surrounding the charging-cone A and the conduits cl.

Below the conduits or lines B there is a flat chamber f, communicating at one extremity with the outside air through the apertures f', opening into the air-space fr, and at the other extremity with the gas-combustion chamber or conduits C through the apertures f2. In

the thickness of the walls comprised between the iiues or conduits B small chambers g are arranged, communicating through the apertures g with the aforesaid chamber f and with the said conduits B through the side apertures g2.

The kiln constructed as described above operates as follows: The kiln is supposed in operation at the moment when a fresh charging is going to be made. The material to be burned (limestone or cement-paste) and the fuel (coke, anthracite, cbc.) are charged in successive layers into the charging-cone A, its cover E being raised. When the charging is effected, the cover E is replaced. It will be noticed that the layers of fuel are thin in proportion to the layers of material, as shown in Fig. l, and that by reason of the cone A widening at its lower part these layers of fuel show a tendency to taper oft' at the borders until when the charge passes by the lower part of the cone A into the shaft A of the kilntheir borders are overspread by the layers of limestone or cement-paste, which descends in a slanting mass into the break or circular cavity a. The layers of fuel are thereby completely inclosed by the limestone, owing to the circular cavity a, and the fuel cannot come in contact with the walls of the shaft A of the kiln and cause the clustering as it occurs at present. The charge of fuel and material to be burned arrives consequently at the Zone of burning, situated at the top of the shaft Al of the kiln, and the burning is performed. At this Zone of burning the fuel and material to be burned disengage carbonio-acid gas, which on passing through the upper fuel, which is heated to a high temperature, forms carbonic oxid, which is discharged by the break or circular cavity and thence it passes to the gas-combustion chamber or conduit C and the fines B, where it is burned, as will be seen later on. A part of this gas passes directly from the cavity a to the chamber C, while another part rises in` the conduits c and circulates in the lines C', escaping from there by the apertures c into the chamber C, where it joins the first part. The purpose of this circulation is to heat the charging-cone A to a high temperature. Besides by this outlet, called continuous lower outlet, the gases escape also by the outlet called intermittentupper outlet, whichworks only when the cover E is closed. This escape takes place above the charge by the circular flue D, the conduits d and the flue D', and from there through the aperture d into the combustion -chamber. As soon as the cover E is raised for a new charging the dampersrare closed, and the gas escapes only by the lower outlet. The continuity of the latter is assured by the judicious opening of the dampers of the chimney into which the iiues B open, which opening causes a draft just feeble enough to draw out the gases without admitting any air to the open charging-cone. The obturation of the charging-cone is then effected by the charge in the cone A and the depression created by the draft of the chimney. When the cover E is closed, the upper outlet comes again into IOO IIO

action. It is therefore really intermittent.

' All the gases disengaged' by the burning are for the purpose of collecting their heating power and utilizing the same in drying-chambers located behind the kiln, where the pastes or limestones to be burned are dried before being fed into the kiln. For this purpose the said gases are mixed with air admitted by the conduits e and the apertures f andg.

. This outside air is strongly heated Iirst and then injected perpcndicularly to the -current of gas to be burned. It will be noticed that these injections operate at different points in such a manner that not a particle of carbonio oXid can pass without being burned.

The currents of gas are indicated by arrows in full lines and the currents of air by'arrows in broken lines.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is l. In combination in a continuous kiln for burning lime, natural and Portland cements, the kiln-shaft, the charging-cone above the same, a break or recess at the top of the shaft and between it andthe charging-cone, a lower gas-outlet leading from the said break, and an upper gas-outlet leading from the charging-cone above the charge of material, airinlets for supplying air to the gases to support combustion thereof and controlling means for making the outlets work together or separatelyaccording as the kiln is operating normally or is being charged, substantially as described.

2. In a continuous kiln for burning lime, cement and the like, the combination with the body-shaft of a kiln, a charging-cone located above the shaft of the kiln, a break or recess at the top of the shaft, a gas-outlet from said recess, or break, located between the kilnshaft and the cone an upper gas-outlet, dampers controlling the latter, air-inlets for supplying'air to the gases to support combustion thereof, a cover over the charging-cone, and connections therefrom to the damper to automatically close the same when the cover is open and to open said outlet when the cover is closed, the lower gas-outlet operating continuously, substantially as described.

3. In combination in continuous kilns for burning lime, natural and Portland cements, the kiln shaft or body, the charging-cone, upper and lower gas-outlets, a gas-combustion space in which the gases from the upper and lower outlets are mixed, and air-conduits for leading air to the gases in the gas-combustion space to mingle therewith, tov support com'- bustion thereof substantially as described.

4,. In a continuous limekiln the combination, of the kiln-shaft, a charging-cone above the same, a break orvrecess at the top of the shaft, an outlet leading from the said break, an' upper outlet leading from the top of vthe chargingfcone, and eXtendin g about said cone, ports through which the gases from said outlets commingle and air-feeding passages leading the air to the gases to support combustion thereof, substantially vas described.

In testimony whereof I havey signed my 'name to this specification in the presence of Witnesses:

LEON CRANEKEN, CLYDE SHRoPsHlRE. 

